code: def testRFFT(self):
      def _to_expected(x):
          return np.fft.rfft(x, n=x.shape[-1])
  
      def _tf_fn(x):
          return signal.rfft(x, fft_length=[x.shape[-1]])
  
      self._VerifyFftMethod(
          INNER_DIMS_1D, np.real, _to_expected, _tf_fn
      )
  
imports: import itertools
  import numpy
  import scipy.signal
  from tensorflow.compiler.tests import xla_test
  from tensorflow.python.framework import dtypes
  from tensorflow.python.ops import array_ops
  from tensorflow.python.ops import gradients_impl
  from tensorflow.python.ops.signal import signal
  from tensorflow.python.platform import googletest
label_desc: Use image node_id 9 for calling the FFTTest obj's underlying member method code with example usage: obj.testRFFT() and returns: np, signal